Telling Travis CI to install our optional dependency. From my understanding of the `npm install ` documentation, and my local npm's behavior, I assume optionalDependencies are installed by default. I can see the flat to not install optional dependencies. I imagine Travis CI's npm is configured to skip optional dependencies, I don't know how to override that. So for now, explicitly installing the one optional dependency we have... which is needed for the CI build.
Telling Travis CI to install our optional dependency. From my understanding of the `npm install ` documentation, and my local npm's behavior, I assume optionalDependencies are installed by default. I can see the flat to not install optional dependencies. I imagine Travis CI's npm is configured to skip optional dependencies, I don't know how to override that. So for now, explicitly installing the one optional dependency we have... which is needed for the CI build.

davidleston/timer,davidleston/timer